1. Lightning

2. Background facts about lightning
Hot enough to melt sand!
Travels at 140,000mph
Is found on Jupiter, Saturn, Venus, Uranus
Not created the same as on earth, but similar
Jupiter
Saturn

3. Background facts about lightning
Average length: 5 Miles long
Record Length over Dallas, TX: 118 Miles long
Unfortunate record
Roy Sullivan
Between 1942 and 1977, struck 7 times and survived them all

4. Lightning can be a variety of colors (blue, green, red)
Caused by what is in the air that the lightning is traveling through
Air makeup also affects the path the lightning will take, and how strong the bolt can be

5. How is lightning created?
Charging by Friction
Ice falling (-)
Water rising (+)
Cloud becomes polarized
(top +, bottom -)
Charging by Friction
Water
Rises
Ice
Falls

6. Induced charge in ground
Negative charges pushed away, leaving positively charged objects on the ground

7. Enough charge is built up and charges flow (lightning bolt)
Dielectric breakdown of air (failure of an insulator) in this case, air (3,000,000 V/m)

8. Leaders and Streamers Step Leaders Streamers Come down from cloud
Come up from Earth
Streamer
Step leader
Streamers
Leaders

9. Leader (from cloud)

10. Streamer (from ground)

11. Fulgurite Lightning melts the sand Forms hollow tubes
$1 -> $2.5 per gram

12. Lightning Safety
Plane refueling

13. People can survive because
How you can get struck
Direct strike
Lighting strikes you directly
Splash Injury
lightning jumps from an object and strikes you
Contact
you are in contact with an object that is struck by lightning
Ground
Lightning can travel through the ground and go up one leg and down the other
People can survive because
Lightning usually doesn’t pass through the heart
Cardiac arrest most common cause of death
Very hot, but passes through your body for only split second

14. Safety Places to avoid Where should you go?
Tall objects, metal objects, wide open areas, water
Don’t use a landline phone
Where should you go?
Inside a building, or in a car (as long as it’s not a convertible)
Not because of the rubber tires!

15. Lightning Safety Faraday Cages
Plane struck by lightning
Start at 0:35
Tesla Coil / Faraday Cage

16. How does a Faraday Cage work?
Faraday cage has to be grounded
Lightning will take the easiest path to ground, through the Faraday Cage

17. Lightning Safety Lightning Rods
Doesn’t always prevent lightning strikes
Gives lightning a path
around your house
Positives attracted to
the top of the rod,
negatives repelled out
of the rod

18. Grounding an Object
Need to bury a grounding rod at least 8ft into the ground
Otherwise, the lightning will spread across the surface of the earth and a
person standing near
could get shocked

19. What about the Fish???
Lighting rarely kills fish because when it strikes water it spreads across the surface, not down into the water
But if a fish is near the surface, it will get fried

20. Lightning Safety Franklin Bells Invented by Ben Franklin
Early warning device to detect lightning storms
One bell hooked up to lightning rod
One bell hooked up to ground
Metal ball in between the bells
To Lightning Rod
To Ground

21. Can lightning be used as an alternative Energy Source?
It can, but it’s not practical
Average bolt won’t even produce enough electricity to power an average house for half a month
Not consistent
Too much current >100,000amps
Average product needs 10-30amps